This invention relates to a shock absorber and more particularly to an improved shock absorber construction for use in vehicles subjected to cold climatic conditions.
As is well known, the suspension system for many types of vehicles includes a shock absorber for damping vibrations encountered when the ground engaging element of the vehicle strikes an obstacle so as to control the movement of the ground engaging element relative to the vehicle body.
These shock absorbers generally comprise an outer cylindrical housing that is closed at one end by an integral wall and which receives a slidably supported piston. The housing is connected to one element of the vehicle. The piston has connected to it a piston rod that extends through the other end of the cylinder housing and which is connected to another element of the vehicle so that the piston and cylinder will move relative to each other during suspension movement. A hydraulic damping arrangement is provided for controlling the flow of fluid from the chambers formed by the piston so as to dampen the vehicle suspension movement.
The end of the piston rod which extends through the open end of the cylinder housing is normally sealed in some manner relative to the cylinder housing so as to define a further fluid chamber on the side of the piston adjacent the otherwise open end of the housing. The piston rod normally slides through this seal and various sealing arrangements are employed so as to ensure against fluid leakage.
Frequently, however, the vehicle is subjected to use in low temperatures and climates where there may be water or snow that can accumulate on the exposed elements of the shock absorber. These climatic conditions can and do cause ice to form on the piston rod of the shock absorber. Since the piston rod may at times be stationary relative to the cylinder, this means that ice can accumulate on the piston rod adjacent the seal. When the vehicle then encounters an obstacle, this ice will be forced into contact with the seal and can damage it and the entire shock absorber mechanism.
There have been proposed the use of resilient scrapers or seals in addition to the fluid seal with a hope that these additional resilient scrapers can remove the ice and prevent damage to the hydraulic seal. However, these resilient seals are not sufficiently rigid so as to remove the accumulated ice. Furthermore, there is a danger that the ice may pass through the resilient scraper and accumulate within the interior of the shock absorber so as to cause corrosion and other possible damage.
It is, therefore, a principle object of this invention to provide an improved shock absorber arrangement for a vehicle.
It is a further object of this invention to provide an improved shock absorber arrangement for a vehicle that is particularly adapted for use in cold climates.
It is another object of this invention to provide an improved ice scraper arrangement for the piston rod of a hydraulic shock absorber for a cold weather vehicle.